Abstract
The immature stages (from egg to pupa) of Culex pipiens molestus (Diptera, mosquito) individuals were exposed to 1, 10, 100, and 1000 μgl-1 of bisphenol A and p-nonylphenol, respectively, with 3 replicates, Hatchability was not affecte significantly at an concentration. Larval mortality increased from 8.5% in the controls to 12 to 22% in the exposed organisms. The emergence rate of the pupae slightly decreased from 0.97in the controls to 0.94 to 0.97 regardless of exposure concentration. The sex ratio of adults (female/male) exposed bisphenol A changed markedly from 1.07 in the controls to 4.70, 3.14 and 0.36 at 100 and 1000 μg1-1, respectively. Exposure to p-nonylpheriol resulted in an increase in the sex ratio between 1.95 and 2.28. The weight of adult males was not affected, while that of adult females decreased with increasing exposure concentrations of the compounds. This may be partly due to the appearance of small females (body weight, ca. 50% of normal female) that emerged from pupae exposed to high concentrations of the two compounds. Hatchability of each egg raft oviposited emerging females decreased from 96.9% in the controls to 25.0 and 55.6% when exposed to 100 and 1000 μg1-1 of bisphenol A, respectively. The decrease in hatchability and a delay in emergence may have been due to the decrease in the proportion of males.
